I know where you're going at, but you can say the same if Scola wasn't in the game. Yao isn't the most efficient rebounder we have, and if Scola was absent we'll easily get outrebounded. Not to mention, Scola exploits open shots and actually makes them. You can say it's because Yao is in the game (even though he always have had the open shots since Yao was out last year), but you can also say that if Scola wasn't in the game you won't have players out there effectively grabbing boards, giving hustles, but make open shots given to them. This can go on and on, and like I said I know people will disagree with me. However, my point emphasizes on the fact that it's not what Scola can do on the court, it's what he can do with what he's given.
The thing is, James does what Mo Williams does but better. Yao can't do many of the things Scola does.